YBCO／Y－ZrO＿2／（1120）蓝宝石多层膜超导材料的分析电镜研究

AEM STUDY ON YBCO/Y-ZrO_2/Y-ZrO_2/SAPPHIRE MULTILAYER SUPERCONDUCTOR

我们在具有Ｙ稳定的ＺｒＯ＿２（ＹＳＺ）层的蓝宝石上获得高质量的ＹＢａ＿２Ｃｕ＿３Ｏ＿７（ＹＢＣＯ）高温超导薄膜。在零磁场下，７７ｋ时，其临界电流密度达到１．６×１０￣６Ａ／ｃｍ￣２。本文确定了多层膜超导材料的取向关系。ＹＢＣＯ膜的（００１）面平行于ＹＳＺ过渡层的（１００）表面。ＹＳＺ层厚为２０ｎｍ。并且，由于Ｂａ自ＹＢＣＯ层的外扩散，ＹＳＺ层含有Ｂａ。尽管蓝宝石与ＹＳＺ层间的晶格铅配很大，由于ＹＳＺ层具有［１００］择优取向，仍能获得准单晶的ＹＢＣＯ薄膜。在ＹＢＣＯ薄膜中，观察到均匀分布的、微小尺寸的Ｙ＿２ＢａＣｕＯ＿５（２１１相）沉淀粒子，它们也有利于提高临界电流密度。

YBa_2Cu_3O_7(YBCO)thin film has been deposited on sapphire with Y-stabilized ZrO_2(YSZ)bufferlayer and shown a high critical transport current density 77 k in zero magnetic field。 Theorientation relationship of the multilayer film superconductor has been determined.The(001)plane of the YB-CO film is parallel to the(100)surface of the YSZ intermediate layer.YSZ buffer layer with(100)preferredorientation is about 20 nm thick and contains element Ba,due to outdiffusion of Ba from YBCO layer。The(100)preferred orientation of YSZ buffer permits the growth of high quality YBCO thin film。Y_2 BaCuO_5 Precip-itates with small size distribute uniformly in the YBCO thin film and are favourable to raise critical current den-sity J_c.